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 ###Instrução: Qual Matrícula tem uma Conferência Primária de mid-hoosier, e um Condado de 16 decatur, e uma Classe IHSAA de aa?
 ###Tabelas: CREATE TABLE pga_tour_professional_career_summary (pga_tour_professional_career_summary_id AUTO_INCREMENT PRIMARY KEY, Year INT, Starts INT, Cuts made VARCHAR, Wins (Majors) VARCHAR, 2nd INT, 3rd INT, Top 10 INT, Top 25 INT, Earnings ($) INT, Money list rank INT, Adjusted scoring average (rank) VARCHAR) CREATE TABLE list_of_games (list_of_games_id AUTO_INCREMENT PRIMARY KEY, Season INT, Date VARCHAR, Venue VARCHAR, City VARCHAR, Visitor VARCHAR, Score VARCHAR, Home VARCHAR, Attendance INT) CREATE TABLE affiliate_members (affiliate_members_id AUTO_INCREMENT PRIMARY KEY, Institution VARCHAR, Location VARCHAR, Founded INT, Type VARCHAR, Enrollment INT, Nickname VARCHAR, Current Conference VARCHAR, Pac-12 Sports VARCHAR) CREATE TABLE newport_rfc_record (newport_rfc_record_id AUTO_INCREMENT PRIMARY KEY, Season VARCHAR, Games INT, Tries INT, Conversions INT, Penalties INT, Drop Goals INT, Total Points INT) CREATE TABLE  (_id AUTO_INCREMENT PRIMARY KEY, School VARCHAR, Location VARCHAR, Mascot VARCHAR, Enrollment INT, IHSAA Class VARCHAR, County VARCHAR, Primary Conference VARCHAR)  
SELECT Enrollment FROM  WHERE Primary Conference = mid-hoosier AND County = 16 decatur AND IHSAA Class = aa